Detachment: This belt is equipped with a quick-release mechanism. In the event of an emergency (e.g. sparking, smoking or extreme vibration) press both sides of the release button with one hand to release the belt. Warning: Please take precaution when adjusting the length of the trimmer line. After adjusting the length of the line, return the trimmer to its normal operating position before starting the unit. Warning: never alter the trimmer by attaching metal cutting blades.